#include <bits/stdc++.h>
#define MAX 100000
using namespace std;
ifstream fin("ctc.in");
ofstream fout("ctc.out");
vector<int>graf[MAX+5], transpus[MAX+5], ctc[MAX+5];
int postordine[MAX+5], nr, n, m, i, x, y;
bool viz[MAX+5];
void dfs(int x) {
    viz[x]=1;
    for (auto y:graf[x]) {
        if (viz[y]==0) {
            dfs(y);
        }
    }
    postordine[++nr]=x;
}
void dfst(int x) {
    viz[x]=0;
    ctc[nr].push_back(x);
    for (auto y:transpus[x]) {
        if (viz[y]==1) {
            dfst(y);
        }
    }
}
int main()
{
    fin>>n>>m;
    for (i=1; i<=m; i++) {
        fin>>x>>y;
        graf[x].push_back(y);
        transpus[y].push_back(x);
    }
    for (i=1; i<=n; i++) if (viz[i]==0) dfs(i);
    for (i=1; i<=n; i++) cout<<postordine[i]<<' ';
    nr=0;
    for (i=n; i>=1; i--) {
        if (viz[postordine[i]]==1) {
            nr++;
            dfst(postordine[i]);
        }
    }
    fout<<nr<<'\n';
    for (i=1; i<=nr; i++) {
        for (auto j:ctc[i]) {
            fout<<j<<' ';
        }
        fout<<'\n';
    }
    return 0;
}